The Soils of The Regional Municipality of Ottawa=Carleton

may also contain shaly layers . Outcrops are most common in
southwestern Rideau Township and northeastern Osgoode
Township, wherethe formation also underlies fairly extensive
areas ofthe shallow Farmington soil association .
Transitional to the Nepean and Oxford formations is the
Ordovician March formation which alternates from grey
sandstone to sandy, blue-grey dolomite (10) . This formation
underlies a portion ofthe City ofKanata .
Of Chazy age are the St . Martin and Rockcliffe formations
(10) . The Rockcliffe formation consists of grey-green
shale with some sandstone lenses . Main areas of occurrence
are in the northern and southern parts of West Carleton
Township, and northern Cumberland Township . The mainly
limestone St . Martin formation outcrops along a narrow
fringe in northern Cumberland Township adjacent to the
Ottawa River .
The Ottawa formation, which is mostly limestone, constitutes
almost as much of the region as the Oxford formation.
Approximately half of both West Carleton and
Cumberland Townships are underlain by this formation . The
upper part of this formation consists of fairly pure limestone
with a few shaly layers (10) . Materials from this formation
continue to be mined and also underlie much of the shallow
Farmington soil association .
Intermittently overlying the Ottawa formation is the
Eastview formation, which consists of dark grey limestone
interbedded with shale (10) . Its only location within the region
is a narrow band which approximately bisects Cumberland
Township from east to west .
Thebrownto black shales ofthe Billings formation overlie
the aforementioned Eastview formation and constitute the
bedrock of central Cumberland Township . This formation is
succeeded by the grey and sandy weathering shales of the
Carlsbad formation in southern Cumberland and northeastern
Osgoode townships . In the same general area, the Carlsbad
formation is in turn succeeded by the Queenston
formation which consists of red shale (10) . The three aforementioned
bedrock formations account for the relatively frequent
occurrence of the shaly Leitrim soil association in
central and southern Cumberland Township . The Queenston
formation is also the original source of the reddish bands of
silt and clay which characterize the Bearbrook soil association
.
Physiography
The Ottawa-Carleton map area consists of parts of four
physiographic regions . These are the Smiths Falls limestone
plain, the North Gower drumlin field, the Ottawa Valley clay
plains, and the Russell Prescott sand plains (13) . Figure 6
shows the predominance of aspects of these four general
regions in comprising the physiography of Ottawa-Carleton .
Figure 7 shows the rivers and main streams of the region .
Table 6 summarizes the relationships between the physiographic
regions, surficial materials, and soils ofthe region .
The Smiths Falls limestone plain includes thewestern half
of Rideau Township, the majority of Goulbourn Township,
and a large part of southernwest Carleton Township . The
topography of this area is generally nearly level, being controlled
by the shallow and mainly limestone and dolomite
Ottawa and Oxford bedrock formations . The thin veneer of
till over the bedrock has been sorted and redeposited as beach
lines in localized spots . Many of these have been mined for
aggregate . Also present are considerable areas of wetlands in
the form of stream and basin swamps and a few fen deposits .
This physiographic area also includes scattered deposits of
deeper clays and sands . Main drainage channels are the
Rideau and the Jock Rivers .
The North Gower drumlin field includes the eastern half
of Rideau Township and the majority of Osgoode Township .
This physiographic region features drumlins and till plains of
gently undulating to moderately sloping topography . Low
areas adjacent to these deposits commonly consist of finer
clays and silts of Champlain Sea origin . These lower deposits
are generally poorly drained . Also present is an esker deposit
flanking the Rideau River on the west side and occurring in a
northsouth direction . This deposit was locally reworked into
beach-type landforms on the surface by the Champlain Sea .
Resulting topography is somewhat subdued with the original
esker flanked by gently sloping sand plains in spots . Intermittent
limestone plains and stream swamp deposits also occur in
the drumlin field area . The Rideau River is the main drainage
channel through the area, serving such minor channels as the
Mud and Steven Creeks . In the eastern part ofthe region, the
smaller South Castor and Castor Rivers are also important
drainage channels . In general, the highproportion ofpoorlydrained
areasin thisphysiographic region has necessitated the
digging ofa considerable municipal drainage network .
The Ottawa Valley clay plains include areas of West
Carleton and Goulbourn townships, the City of Kanata, and
the majority of Cumberland Township . West of the City of
Ottawa, the physiography is acombination of clay plains and
bedrock uplands which is due to faulting . Agood example of
this phenomenon is the Carp Valley and the adjacent Carp
Ridge, demarcated from each other by the Hazeldean fault .
East of the City of Ottawa, in Cumberland Township, the
clay plain borders the present Ottawa River . Further to the
south across the middle ofthe township, the more or less uniform
clay plain borders an ancient abandoned channel of the
Ottawa River . The channel varies from 3 to 5 km, wide and
was abandoned due to isostatic uplift of the land surface following
glacial retreat . This caused the channel to rise above
sea level, therefore confining the river to its modern northern
route . Part of the channel is now drained by the Bear Brook,
but it is alsothesite ofthe poorly drained Mer Bleue bog inthe
western portion . Most of the channel consists of clay plains
alternating with sandy deposits and modified till plains .A few
ancient landslide sites are also present (12) . Main drainage
channels besides the Ottawa River in theclay plains region are
the Mississippi River, Carp River, Cardinal Creek, Becketts
Creek, as well asthe Bear Brook .
To the south of the ancient river channel, in the remainder
of Cumberland Township and northern Osgoode Township,
the area is part of the Russell Prescott sand plains
physiographic region . These sand deposits were originally
part ofa delta of the early Ottawa River . The delta was subsequently
incised during the events of isostatic uplift of the
regional land mass and the resulting recession and rerouting
ofthe river's waters . The remainingdeposits are generally 5 to
10 m thick, and level to very gently undulating except where
theyhave been reworked into dunes . Main drainage channels
in this area are the North Castor River, Shaws Creek, and the
South Indian Creek .